Lightly butter 9x13 glass pan, layer one layer of chocolate graham crackers. Mix Jell-O pudding with milk and stir until completely mixed, fold in Cool Whip. Pour half of this mixture over graham cracker layer. Place another layer of graham crackers and pour remaining mixture on top. Place another layer of graham crackers.
Microwave frosting for approximately 30 second until melted. Mix with peanut butter and pour over top layer of graham crackers.